The present invention relates to socket drive tools and, in particular, to drive tools with quick release mechanisms to facilitate mounting and demounting of associated sockets on the drive tool
A socket drive tool typically has a drive lug at one end, usually square in transverse cross section, adapted to be mateably received in a square drive receptacle end of the associated socket tool. The square drive lug on the drive tool usually has a detent ball seated in a recess and spring loaded outwardly for engagement in a complementary recess in the inner face of the socket, to resiliently retain the socket in place on the drive tool. The spring loading force on the ball is usually such as to permit manual mounting and demounting of the socket on the drive tool, while inhibiting inadvertent disconnection of the parts.
It is known to provide a locking type of mechanism for such a detent ball, wherein a pin or similar member reciprocates in a bore in the drive tool between a retaining condition, wherein the pin forces the ball out of the recess, and a releasing condition, wherein the pin is retracted to allow retraction of the ball into the recess. Typically the pin is spring loaded to its retaining condition and is manually movable to its retracted or releasing condition by means of an actuator member, which is coupled to the pin but is manually accessible by a user to reciprocate with the pin. Commonly, such quick-release arrangements are designed so that when the pin is in its retaining condition, the detent ball is locked in its outwardly projecting or socket-retaining position, so that a socket either cannot be mounted or demounted or is very difficult to mount and demount manually. When the detent ball is recessed by retracting the pin to its releasing condition, the socket can be easily mounted and demounted without interference by the detent ball. However, the use of a reciprocating actuator for effecting movement of the reciprocating pin is mechanically inefficient and may require the exertion of considerable force by the user's finger, thumb or the like.